And champs spamming snap.
And taekwons spamming high jump.
It's the same concept; it's not the skill that annoys us, it's the running.
I use backslide rarely myself to escape out of imminent danger, so I can switch a shield or so; but I don't run, I come back after adapting.
Edit: To give an example, if I'm fighting a TSS champ with no shield on, and he's TSSing me while I move closer to him, and I see him stop TSSing and zen/fury/zen, I use backslide quickly and then put on a shield, instead of just putting on a shield since it takes me longer to move my mouse to my inventory and double click it than it takes him to press a button and click me.
My mouse is shit.